@article{DuyduBasaranAydinetal.2018,
  author    = {Duydu, Yalcin and Basaran, Nursen and Aydin, Sevtap and Ustundag, Aylin and Yalcin, Can {\"O}zg{\"u}r and Anlar, Hatice Gul and Bacanli, Merve and Aydos, Kaan and Atabekoglu, Cem Somer and Golka, Klaus and Ickstadt, Katja and Schwerdtle, Tanja and Werner, Matthias and Meyer, S{\"o}ren and Bolt, Hermann M.},
  title     = {Evaluation of FSH, LH, testosterone levels and semen parameters in male boron workers under extreme exposure conditions},
  series = {Archives of toxicology : official journal of EUROTOX},
  volume    = {92},
  journal   = {Archives of toxicology : official journal of EUROTOX},
  number    = {10},
  publisher = {Springer},
  address   = {Heidelberg},
  issn      = {0340-5761},
  doi       = {10.1007/s00204-018-2296-7},
  pages     = {3051 -- 3059},
  year      = {2018},
  abstract  = {Boric acid and sodium borates are currently classified in the EU-CLP regulation as "toxic to reproduction" under "Category 1B", with hazard statement of H360FD. However, so far field studies on male reproduction in China and in Turkey could not confirm such boron-associated toxic effects. As validation by another independent study is still required, the present study has investigated possible boron-associated effects on male reproduction in workers (n = 212) under different boron exposure conditions. The mean daily boron exposure (DBE) and blood boron concentration of workers in the extreme exposure group (n = 98) were 47.17 +/- 17.47 (7.95-106.8) mg B/day and 570.6 +/- 160.1 (402.6-1100) ng B/g blood, respectively. Nevertheless, boron-associated adverse effects on semen parameters, as well as on FSH, LH and total testosterone levels were not seen, even within the extreme exposure group. With this study, a total body of evidence has accumulated that allows to conclude that male reproductive effects are not relevant to humans, under any feasible and realistic conditions of exposure to inorganic boron compounds.},
  language  = {en}
}
@article{WittEbertMeyeretal.2017,
  author    = {Witt, Barbara and Ebert, Franziska and Meyer, S{\"o}ren and Francesconi, Kevin A. and Schwerdtle, Tanja},
  title     = {Assessing neurodevelopmental effects of arsenolipids in pre-differentiated human neurons},
  series = {Molecular nutrition \& food research : bioactivity, chemistry, immunology, microbiology, safety, technology},
  volume    = {61},
  journal   = {Molecular nutrition \& food research : bioactivity, chemistry, immunology, microbiology, safety, technology},
  publisher = {Wiley},
  address   = {Hoboken},
  issn      = {1613-4125},
  doi       = {10.1002/mnfr.201700199},
  pages     = {10},
  year      = {2017},
  abstract  = {Scope: In the general population exposure to arsenic occurs mainly via diet. Highest arsenic concentrations are found in seafood, where arsenic is present predominantly in its organic forms including arsenolipids. Since recent studies have provided evidence that arsenolipids could reach the brain of an organism and exert toxicity in fully differentiated human neurons, this work aims to assess the neurodevelopmental toxicity of arsenolipids. Methods and results: Neurodevelopmental effects of three arsenic-containing hydrocarbons (AsHC), two arsenic-containing fatty acids (AsFA), arsenite and dimethylarsinic acid (DMA(V)) were characterized in pre-differentiated human neurons. AsHCs and arsenite caused substantial cytotoxicity in a similar, low concentration range, whereas AsFAs and DMA(V) were less toxic. AsHCs were highly accessible for cells and exerted pronounced neurodevelopmental effects, with neurite outgrowth and the mitochondrial membrane potential being sensitive endpoints; arsenite did not substantially decrease those two endpoints. In fully differentiated neurons, arsenite and AsHCs caused neurite toxicity. Conclusion: These results indicate for a neurodevelopmental potential of AsHCs. Taken into account the possibility that AsHCs might easily reach the developing brain when exposed during early life, neurotoxicity and neurodevelopmental toxicity cannot be excluded. Further studies are needed in order to progress the urgently needed risk assessment.},
  language  = {en}
}
@article{WittMeyerEbertetal.2017,
  author    = {Witt, Barbara and Meyer, S{\"o}ren and Ebert, Franziska and Francesconi, Kevin A. and Schwerdtle, Tanja},
  title     = {Toxicity of two classes of arsenolipids and their water-soluble metabolites in human differentiated neurons},
  series = {Archives of toxicology : official journal of EUROTOX},
  volume    = {91},
  journal   = {Archives of toxicology : official journal of EUROTOX},
  publisher = {Springer},
  address   = {Heidelberg},
  issn      = {0340-5761},
  doi       = {10.1007/s00204-017-1933-x},
  pages     = {3121 -- 3134},
  year      = {2017},
  abstract  = {Arsenolipids are lipid-soluble organoarsenic compounds, mainly occurring in marine organisms, with arsenic-containing hydrocarbons (AsHCs) and arsenic-containing fatty acids (AsFAs) representing two major subgroups. Recently, toxicity studies of several arsenolipids showed a high cytotoxic potential of those arsenolipids in human liver and bladder cells. Furthermore, feeding studies with Drosophila melanogaster indicated an accumulation of arsenolipids in the fruit fly's brain. In this study, the neurotoxic potential of three AsHCs, two AsFAs and three metabolites (dimethylarsinic acid, thio/oxo-dimethylarsenopropanoic acid) was investigated in comparison to the toxic reference arsenite (iAsIII) in fully differentiated human brain cells (LUHMES cells). Thereby, in the case of AsHCs both the cell number and cell viability were reduced in a low micromolar concentration range comparable to iAsIII, while AsFAs and the applied metabolites were less toxic. Mechanistic studies revealed that AsHCs reduced the mitochondrial membrane potential, whereas neither iAsIII nor AsFAs had an impact. Furthermore, neurotoxic mechanisms were investigated by examining the neuronal network. Here, AsHCs massively disturbed the neuronal network and induced apoptotic effects, while iAsIII and AsFAs showed comparatively lesser effects. Taking into account the substantial in vitro neurotoxic potential of the AsHCs and the fact that they could transfer across the physiological barriers of the brain, a neurotoxic potential in vivo for the AsHCs cannot be excluded and needs to be urgently characterized.},
  language  = {en}
}
@article{MeyerMatissekMuelleretal.2014,
  author    = {Meyer, S{\"o}ren and Matissek, M. and M{\"u}ller, Sandra Marie and Taleshi, M. S. and Ebert, Franziska and Francesconi, Kevin A. and Schwerdtle, Tanja},
  title     = {In vitro toxicological characterisation of three arsenic-containing hydrocarbons},
  series = {Metallomics},
  volume    = {2014},
  journal   = {Metallomics},
  number    = {6},
  issn      = {1756-591X},
  doi       = {10.1039/c4mt00061g},
  pages     = {1023 -- 1033},
  year      = {2014},
  abstract  = {Arsenic-containing hydrocarbons are one group of fat-soluble organic arsenic compounds (arsenolipids) found in marine fish and other seafood. A risk assessment of arsenolipids is urgently needed, but has not been possible because of the total lack of toxicological data. In this study the cellular toxicity of three arsenic-containing hydrocarbons was investigated in cultured human bladder (UROtsa) and liver (HepG2) cells. Cytotoxicity of the arsenic-containing hydrocarbons was comparable to that of arsenite, which was applied as the toxic reference arsenical. A large cellular accumulation of arsenic, as measured by ICP-MS/MS, was observed after incubation of both cell lines with the arsenolipids. Moreover, the toxic mode of action shown by the three arsenic-containing hydrocarbons seemed to differ from that observed for arsenite. Evidence suggests that the high cytotoxic potential of the lipophilic arsenicals results from a decrease in the cellular energy level. This first in vitro based risk assessment cannot exclude a risk to human health related to the presence of arsenolipids in seafood, and indicates the urgent need for further toxicity studies in experimental animals to fully assess this possible risk.},
  language  = {en}
}
@misc{MeyerMatissekMuelleretal.2014,
  author    = {Meyer, S{\"o}ren and Matissek, M. and M{\"u}ller, Sandra Marie and Taleshi, M. S. and Ebert, Franziska and Francesconi, Kevin A. and Schwerdtle, Tanja},
  title     = {In vitro toxicological characterisation of three arsenic-containing hydrocarbons},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-74201},
  pages     = {1023 -- 1033},
  year      = {2014},
  abstract  = {Arsenic-containing hydrocarbons are one group of fat-soluble organic arsenic compounds (arsenolipids) found in marine fish and other seafood. A risk assessment of arsenolipids is urgently needed, but has not been possible because of the total lack of toxicological data. In this study the cellular toxicity of three arsenic-containing hydrocarbons was investigated in cultured human bladder (UROtsa) and liver (HepG2) cells. Cytotoxicity of the arsenic-containing hydrocarbons was comparable to that of arsenite, which was applied as the toxic reference arsenical. A large cellular accumulation of arsenic, as measured by ICP-MS/MS, was observed after incubation of both cell lines with the arsenolipids. Moreover, the toxic mode of action shown by the three arsenic-containing hydrocarbons seemed to differ from that observed for arsenite. Evidence suggests that the high cytotoxic potential of the lipophilic arsenicals results from a decrease in the cellular energy level. This first in vitro based risk assessment cannot exclude a risk to human health related to the presence of arsenolipids in seafood, and indicates the urgent need for further toxicity studies in experimental animals to fully assess this possible risk.},
  language  = {en}
}
@phdthesis{Meyer2015,
  author    = {Meyer, S{\"o}ren},
  title     = {Toxicity and toxicokinetics of arsenolipids and their metabolites},
  school      = {Universit{\"a}t Potsdam},
  pages     = {152, VIII},
  year      = {2015},
  language  = {en}
}
@article{DuyduBasaranUstundagetal.2018,
  author    = {Duydu, Yalcin and Basaran, Nursen and Ustundag, Aylin and Aydin, Sevtap and Yalcin, Can Ozgur and Anlar, Hatice Gul and Bacanli, Merve and Aydos, Kaan and Atabekoglu, Cem Somer and Golka, Klaus and Ickstadt, Katja and Schwerdtle, Tanja and Werner, Matthias and Meyer, S{\"o}ren and Bolt, Hermann M.},
  title     = {Birth weights of newborns and pregnancy outcomes of environmentally boron-exposed females in Turkey},
  series = {Archives of toxicology : official journal of EUROTOX},
  volume    = {92},
  journal   = {Archives of toxicology : official journal of EUROTOX},
  number    = {8},
  publisher = {Springer},
  address   = {Heidelberg},
  issn      = {0340-5761},
  doi       = {10.1007/s00204-018-2238-4},
  pages     = {2475 -- 2485},
  year      = {2018},
  abstract  = {Boric acid and sodium borates are currently classified as being toxic to reproduction under "Category 1B" with the hazard statement of "H360 FD" in the European CLP regulation. This has prompted studies on boron-mediated reprotoxic effects in male workers in boron mining areas and boric acid production plants. By contrast, studies on boron-mediated developmental effects in females are scarce. The present study was designed to fill this gap. Hundred and ninety nine females residing in Bandirma and Bigadic participated in this study investigating pregnancy outcomes. The participants constituted a study group covering blood boron from low (< 100 ng B/g blood, n = 143) to high (> 150 ng B/g blood, n = 27) concentrations. The mean blood boron concentration and the mean estimated daily boron exposure of the high exposure group was 274.58 (151.81-975.66) ng B/g blood and 24.67 (10.47-57.86) mg B/day, respectively. In spite of the high level of daily boron exposure, boron-mediated adverse effects on induced abortion, spontaneous abortion (miscarriage), stillbirth, infant death, neonatal death, early neonatal death, preterm birth, congenital anomalies, sex ratio and birth weight of newborns were not observed.},
  language  = {en}
}
@article{BasaranDuyduUstundagetal.2019,
  author    = {Basaran, Nursen and Duydu, Yalcin and Ustundag, Aylin and Taner, Gokce and Aydin, Sevtap and Anlar, Hatice Gul and Yalcin, Can {\"O}zg{\"u}r and Bacanli, Merve and Aydos, Kaan and Atabekoglu, Cem Somer and Golka, Klaus and Ickstadt, Katja and Schwerdtle, Tanja and Werner, Matthias and Meyer, S{\"o}ren and Bolt, Hermann M.},
  title     = {Evaluation of the DNA damage in lymphocytes, sperm and buccal cells of workers under environmental and occupational boron exposure conditions},
  series = {Mutation Research/Genetic Toxicology and Environmental Mutagenesis},
  volume    = {843},
  journal   = {Mutation Research/Genetic Toxicology and Environmental Mutagenesis},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {1383-5718},
  doi       = {10.1016/j.mrgentox.2018.12.013},
  pages     = {33 -- 39},
  year      = {2019},
  abstract  = {Industrial production and use of boron compounds have increased during the last decades, especially for the manufacture of borosilicate glass, fiberglass, metal alloys and flame retardants. This study was conducted in two districts of Balikesir; Bandirma and Bigadic, which geographically belong to the Marmara Region of Turkey. Bandirma is the production and exportation zone for the produced boric acid and some borates and Bigadic has the largest B deposits in Turkey. 102 male workers who were occupationally exposed to boron from Bandirma and 110 workers who were occupationally and environmentally exposed to boron from Bigadic participated to our study. In this study the DNA damage in the sperm, blood and buccal cells of 212 males was evaluated by comet and micronucleus assays. No significant increase in the DNA damage in blood, sperm and buccal cells was observed in the residents exposed to boron both occupationally and environmentally (p = 0.861) for Comet test in the sperm samples, p = 0.116 for Comet test in the lymphocyte samples, p = 0.042 for micronucleus (MN) test, p = 0.955 for binucleated cells (BN), p = 1.486 for condensed chromatin (CC), p = 0.455 for karyorrhectic cells (KHC), p = 0.541 for karyolitic cells (KLY), p = 1.057 for pyknotic cells (PHC), p = 0.331 for nuclear bud (NBUD)). No correlations were seen between blood boron levels and tail intensity values of the sperm samples, lymphocyte samples, frequencies of MN, BN, KHC, KYL, PHC and NBUD. The results of this study came to the same conclusions of the previous studies that boron does not induce DNA damage even under extreme exposure conditions.},
  language  = {en}
}
@article{MeyerLopezSerranoMitzeetal.2017,
  author    = {Meyer, S{\"o}ren and Lopez-Serrano, Aniceto and Mitze, Hanna and Jakubowski, Norbert and Schwerdtle, Tanja},
  title     = {Single-cell analysis by ICP-MS/MS as a fast tool for cellular bioavailability studies of arsenite},
  series = {Metallomics : integrated biometal science},
  volume    = {10},
  journal   = {Metallomics : integrated biometal science},
  number    = {1},
  publisher = {Royal Society of Chemistry},
  address   = {Cambridge},
  issn      = {1756-5901},
  doi       = {10.1039/c7mt00285h},
  pages     = {73 -- 76},
  year      = {2017},
  abstract  = {Single-cell inductively coupled plasma mass spectrometry (SC-ICP-MS) has become a powerful and fast tool to evaluate the elemental composition at a single-cell level. In this study, the cellular bioavailability of arsenite (incubation of 25 and 50 mu M for 0-48 h) has been successfully assessed by SC-ICP-MS/MS for the first time directly after re-suspending the cells in water. This procedure avoids the normally arising cell membrane permeabilization caused by cell fixation methods (e.g. methanol fixation). The reliability and feasibility of this SC-ICP-MS/MS approach with a limit of detection of 0.35 fg per cell was validated by conventional bulk ICP-MS/MS analysis after cell digestion and parallel measurement of sulfur and phosphorus.},
  language  = {en}
}
@article{MeyerMarkovaPohletal.2018,
  author    = {Meyer, S{\"o}ren and Markova, Mariya and Pohl, Gabriele and Marschall, Talke Anu and Pivovarova, Olga and Pfeiffer, Andreas F. H. and Schwerdtle, Tanja},
  title     = {Development, validation and application of an ICP-MS/MS method to quantify minerals and (ultra-)trace elements in human serum},
  series = {Journal of trace elements in medicine and biology},
  volume    = {49},
  journal   = {Journal of trace elements in medicine and biology},
  publisher = {Elsevier GMBH},
  address   = {M{\"u}nchen},
  issn      = {0946-672X},
  doi       = {10.1016/j.jtemb.2018.05.012},
  pages     = {157 -- 163},
  year      = {2018},
  abstract  = {Multi-element determination in human samples is very challenging. Especially in human intervention studies sample volumes are often limited to a few microliters and due to the high number of samples a high-throughput is indispensable. Here, we present a state-of-the-art ICP-MS/MS-based method for the analysis of essential (trace) elements, namely Mg, Ca, Fe, Cu, Zn, Mo, Se and I, as well as food-relevant toxic elements such as As and Cd. The developed method was validated regarding linearity of the calibration curves, method LODs and LOQs, selectivity and trueness as well as precision. The established reliable method was applied to quantify the element serum concentrations of participants of a human intervention study (LeguAN). The participants received isocaloric diets, either rich in plant protein or in animal protein. While the serum concentrations of Mg and Mo increased in participants receiving the plant protein-based diet (above all legumes), the Se concentration in serum decreased. In contrast, the animal protein-based diet, rich in meat and dairy products, resulted in an increased Se concentration in serum.},
  language  = {en}
}
@article{DuenkelbergMaywaldSchmittetal.2020,
  author    = {D{\"u}nkelberg, Sophie and Maywald, Martina and Schmitt, Anne Kristina and Schwerdtle, Tanja and Meyer, S{\"o}ren and Rink, Lothar},
  title     = {The interaction of sodium and zinc in the priming of T cell subpopulations regarding Th17 and Treg cells},
  series = {Molecular nutrition \& food research : bioactivity, chemistry, immunology, microbiology, safety, technology},
  volume    = {64},
  journal   = {Molecular nutrition \& food research : bioactivity, chemistry, immunology, microbiology, safety, technology},
  number    = {2},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {1613-4133},
  doi       = {10.1002/mnfr.201900245},
  pages     = {10},
  year      = {2020},
  abstract  = {Scope: Nutrition is a critical determinant of a functional immune system. The aim of this study is to investigate the molecular mechanisms by which immune cells are influenced by zinc and sodium. Methods and Results: Mixed lymphocyte cultures and Jurkat cells are generated and incubated with zinc, sodium, or a combination of both for further tests. Zinc induces the number of regulatory T cells (Treg) and decreases T helper 17 cells (Th17), and sodium has the opposite effect. The transforming growth factor beta receptor signaling pathway is also enhanced by zinc and reduced by sodium as indicated by contrary phosphoSmad 2/3 induction. Antagonistic effects can also be seen on zinc transporter and metallothionein-1 (MT-1) mRNA expression: zinc declines Zip10 mRNA expression while sodium induces it, whereas MT-1 mRNA expression is induced by zinc while it is reduced by sodium. Conclusion: This data indicate that zinc and sodium display opposite effects regarding Treg and Th17 induction in MLC, respectively, resulting in a contrary effect on the immune system. Additionally, it reveals a direct interaction of zinc and sodium in the priming of T cell subpopulations and shows that Zip10 and MT-1 play a significant role in those differentiation pathways.},
  language  = {en}
}
@article{BrothersHiltMeyeretal.2013,
  author    = {Brothers, Soren M. and Hilt, Sabine and Meyer, Stephanie and K{\"o}hler, Jan},
  title     = {Plant community structure determines primary productivity in shallow, eutrophic lakes},
  series = {Freshwater biology},
  volume    = {58},
  journal   = {Freshwater biology},
  number    = {11},
  publisher = {Wiley-Blackwell},
  address   = {Hoboken},
  issn      = {0046-5070},
  doi       = {10.1111/fwb.12207},
  pages     = {2264 -- 2276},
  year      = {2013},
  abstract  = {Regime shifts are commonly associated with the loss of submerged macrophytes in shallow lakes; yet, the effects of this on whole-lake primary productivity remain poorly understood. This study compares the annual gross primary production (GPP) of two shallow, eutrophic lakes with different plant community structures but similar nutrient concentrations. Daily GPP rates were substantially higher in the lake containing submerged macrophytes (58623gCm(-2)year(-1)) than in the lake featuring only phytoplankton and periphyton (40823gCm(-2)year(-1); P<0.0001). Comparing lake-centre diel oxygen curves to compartmental estimates of GPP confirmed that single-site oxygen curves may provide unreliable estimates of whole-lake GPP. The discrepancy between approaches was greatest in the macrophyte-dominated lake during the summer, with a high proportion of GPP occurring in the littoral zone. Our empirical results were used to construct a simple conceptual model relating GPP to nutrient availability for these alternative ecological regimes. This model predicted that lakes featuring submerged macrophytes may commonly support higher rates of GPP than phytoplankton-dominated lakes, but only within a moderate range of nutrient availability (total phosphorus ranging from 30 to 100gL(-1)) and with mean lake depths shallower than 3 or 4m. We conclude that shallow lakes with a submerged macrophyte-epiphyton complex may frequently support a higher annual primary production than comparable lakes that contain only phytoplankton and periphyton. We thus suggest that a regime shift involving the loss of submerged macrophytes may decrease the primary productivity of many lakes, with potential consequences for the entire food webs of these ecosystems.},
  language  = {en}
}
@article{MeyerMatissekMuelleretal.2014,
  author    = {Meyer, S{\"o}ren and Matissek, M. and Mueller, S. M. and Taleshi, M. S. and Ebert, Franziska and Francesconi, Kevin A. and Schwerdtle, Tanja},
  title     = {In vitro toxicological characterisation of three arsenic-containing hydrocarbons},
  series = {Metallomics : integrated biometal science},
  volume    = {6},
  journal   = {Metallomics : integrated biometal science},
  number    = {5},
  publisher = {Royal Society of Chemistry},
  address   = {Cambridge},
  issn      = {1756-5901},
  doi       = {10.1039/c4mt00061g},
  pages     = {1023 -- 1033},
  year      = {2014},
  abstract  = {Arsenic-containing hydrocarbons are one group of fat-soluble organic arsenic compounds (arsenolipids) found in marine fish and other seafood. A risk assessment of arsenolipids is urgently needed, but has not been possible because of the total lack of toxicological data. In this study the cellular toxicity of three arsenic-containing hydrocarbons was investigated in cultured human bladder (UROtsa) and liver (HepG2) cells. Cytotoxicity of the arsenic-containing hydrocarbons was comparable to that of arsenite, which was applied as the toxic reference arsenical. A large cellular accumulation of arsenic, as measured by ICP-MS/MS, was observed after incubation of both cell lines with the arsenolipids. Moreover, the toxic mode of action shown by the three arsenic-containing hydrocarbons seemed to differ from that observed for arsenite. Evidence suggests that the high cytotoxic potential of the lipophilic arsenicals results from a decrease in the cellular energy level. This first in vitro based risk assessment cannot exclude a risk to human health related to the presence of arsenolipids in seafood, and indicates the urgent need for further toxicity studies in experimental animals to fully assess this possible risk.},
  language  = {en}
}
@article{KoehlerLutherMeyeretal.2014,
  author    = {K{\"o}hler, Yvonne and Luther, Eva Maria and Meyer, S{\"o}ren and Schwerdtle, Tanja and Dringen, Ralf},
  title     = {Uptake and toxicity of arsenite and arsenate in cultured brain astrocytes},
  series = {Journal of trace elements in medicine and biology},
  volume    = {28},
  journal   = {Journal of trace elements in medicine and biology},
  number    = {3},
  publisher = {Elsevier},
  address   = {Jena},
  issn      = {0946-672X},
  doi       = {10.1016/j.jtemb.2014.04.007},
  pages     = {328 -- 337},
  year      = {2014},
  abstract  = {Inorganic arsenicals are environmental toxins that have been connected with neuropathies and impaired cognitive functions. To investigate whether such substances accumulate in brain astrocytes and affect their viability and glutathione metabolism, we have exposed cultured primary astrocytes to arsenite or arsenate. Both arsenicals compromised the cell viability of astrocytes in a time- and concentration-dependent manner. However, the early onset of cell toxicity in arsenite-treated astrocytes revealed the higher toxic potential of arsenite compared with arsenate. The concentrations of arsenite and arsenate that caused within 24 h half-maximal release of the cytosolic enzyme lactate dehydrogenase were around 0.3 mM and 10 mM, respectively. The cellular arsenic contents of astrocytes increased rapidly upon exposure to arsenite or arsenate and reached after 4 h of incubation almost constant steady state levels. These levels were about 3-times higher in astrocytes that had been exposed to a given concentration of arsenite compared with the respective arsenate condition. Analysis of the intracellular arsenic species revealed that almost exclusively arsenite was present in viable astrocytes that had been exposed to either arsenate or arsenite. The emerging toxicity of arsenite 4 h after exposure was accompanied by a loss in cellular total glutathione and by an increase in the cellular glutathione disulfide content. These data suggest that the high arsenite content of astrocytes that had been exposed to inorganic arsenicals causes an increase in the ratio of glutathione disulfide to glutathione which contributes to the toxic potential of these substances.},
  language  = {en}
}
@article{MayerUciechowskiMeyeretal.2014,
  author    = {Mayer, Lena S. and Uciechowski, Peter and Meyer, S{\"o}ren and Schwerdtle, Tanja and Rink, Lothar and Haase, Hajo},
  title     = {Differential impact of zinc deficiency on phagocytosis, oxidative burst, and production of pro-inflammatory cytokines by human monocytes},
  series = {Metallomics : integrated biometal science},
  volume    = {6},
  journal   = {Metallomics : integrated biometal science},
  number    = {7},
  publisher = {Royal Society of Chemistry},
  address   = {Cambridge},
  issn      = {1756-5901},
  doi       = {10.1039/c4mt00051j},
  pages     = {1288 -- 1295},
  year      = {2014},
  language  = {en}
}
@article{MeyerSchulzJeibmannetal.2014,
  author    = {Meyer, S{\"o}ren and Schulz, J. and Jeibmann, A. and Taleshi, M. S. and Ebert, Franziska and Francesconi, Kevin A. and Schwerdtle, Tanja},
  title     = {Arsenic-containing hydrocarbons are toxic in the in vivo model Drosophila melanogaster},
  series = {Metallomics : integrated biometal science},
  volume    = {6},
  journal   = {Metallomics : integrated biometal science},
  number    = {11},
  publisher = {Royal Society of Chemistry},
  address   = {Cambridge},
  issn      = {1756-5901},
  doi       = {10.1039/c4mt00249k},
  pages     = {2010 -- 2014},
  year      = {2014},
  abstract  = {Arsenic-containing hydrocarbons (AsHC) constitute one group of arsenolipids that have been identified in seafood. In this first in vivo toxicity study for AsHCs, we show that AsHCs exert toxic effects in Drosophila melanogaster in a concentration range similar to that of arsenite. In contrast to arsenite, however, AsHCs cause developmental toxicity in the late developmental stages of Drosophila melanogaster. This work illustrates the need for a full characterisation of the toxicity of AsHCs in experimental animals to finally assess the risk to human health related to the presence of arsenolipids in seafood.},
  language  = {en}
}
@article{NiehoffBauerKroegeretal.2015,
  author    = {Niehoff, Ann-Christin and Bauer, Oliver Bolle and Kr{\"o}ger, Sabrina and Fingerhut, Stefanie and Schulz, Jacqueline and Meyer, S{\"o}ren and Sperling, Michael and Jeibmann, Astrid and Schwerdtle, Tanja and Karst, Uwe},
  title     = {Quantitative Bioimaging to Investigate the Uptake of Mercury Species in Drosophila melanogaster},
  series = {Analytical chemistry},
  volume    = {87},
  journal   = {Analytical chemistry},
  number    = {20},
  publisher = {American Chemical Society},
  address   = {Washington},
  issn      = {0003-2700},
  doi       = {10.1021/acs.analchem.5b02500},
  pages     = {10392 -- 10396},
  year      = {2015},
  abstract  = {The uptake of mercury species in the model organism Drosophila melanogaster was investigated by elemental bioimaging using laser ablation-inductively coupled plasma mass spectrometry (LA-ICPMS). The mercury distribution in Drosophila melanogaster was analyzed for the three species mercury(II) chloride, methylmercury chloride, and thimerosal after intoxication. A respective analytical method was developed and applied to the analysis of the entire Drosophila melanogaster first, before a particular focus was directed to the cerebral areas of larvae and adult flies. For quantification of mercury, matrix-matched standards based on gelatin were prepared. Challenges of spatially dissolved mercury determination, namely, strong evaporation issues of the analytes and an inhomogeneous distribution of mercury in the standards due to interactions with cysteine containing proteins of the gelatin were successfully addressed by complexation with meso-2,3-dimercaptosuccinic acid (DMSA). No mercury was detected in the cerebral region for mercury(II) chloride, whereas both organic species showed the ability to cross the blood brain barrier. Quantitatively, the mercury level in the brain exceeded the fed concentration indicating mercury enrichment, which was approximately 3 times higher for methylmercury chloride than for thimerosal.},
  language  = {en}
}
@article{MeyerRaberEbertetal.2015,
  author    = {Meyer, S{\"o}ren and Raber, Georg and Ebert, Franziska and Taleshi, Mojtaba S. and Francesconi, Kevin A. and Schwerdtle, Tanja},
  title     = {Arsenic-containing hydrocarbons and arsenic-containing fatty acids: Transfer across and presystemic metabolism in the Caco-2 intestinal barrier model},
  series = {Molecular nutrition \& food research : bioactivity, chemistry, immunology, microbiology, safety, technology},
  volume    = {59},
  journal   = {Molecular nutrition \& food research : bioactivity, chemistry, immunology, microbiology, safety, technology},
  number    = {10},
  publisher = {Wiley-Blackwell},
  address   = {Hoboken},
  issn      = {1613-4125},
  doi       = {10.1002/mnfr.201500286},
  pages     = {2044 -- 2056},
  year      = {2015},
  abstract  = {Scope: Arsenic-containing hydrocarbons (AsHCs) and arsenic-containing fatty acids (AsFAs) represent two classes of arsenolipids occurring naturally in marine food. Toxicological data are yet scarce and an assessment regarding the risk to human health has not been possible. Here, we investigated the transfer and presystemic metabolism of five arsenolipids in an intestinal barrier model. Methods and results: Three AsHCs and two AsFAs were applied to the Caco-2 intestinal barrier model. Thereby, the short-chain AsHCs reached up to 50\% permeability. Transport is likely to occur via passive diffusion. The AsFAs showed lower intestinal bioavailability, but respective permeabilities were still two to five times higher as compared to arsenobetaine or arsenosugars. Interestingly, AsFAs were effectively biotransformed while passing the in vitro intestinal barrier, whereas AsHCs were transported to the blood-facing compartment essentially unchanged. Conclusion: AsFAs can be presystemically metabolised and the amount of transferred arsenic is lower than that for AsHCs. In contrast, AsHCs are likely to be highly intestinally bioavailable to humans. Since AsHCs exert strong toxicity in vitro and in vivo, toxicity studies with experimental animals as well as a human exposure assessment are needed to assess the risk to human health related to the presence of AsHCs in seafood.},
  language  = {en}
}
@article{RosenkranzMaywaldHilgersetal.2016,
  author    = {Rosenkranz, Eva and Maywald, Martina and Hilgers, Ralf-Dieter and Brieger, Anne and Clarner, Tim and Kipp, Markus and Pluemaekers, Birgit and Meyer, S{\"o}ren and Schwerdtle, Tanja and Rink, Lothar},
  title     = {Induction of regulatory T cells in Th1-/Th17-driven experimental autoimmune encephalomyelitis by zinc administration},
  series = {The journal of nutritional biochemistry},
  volume    = {29},
  journal   = {The journal of nutritional biochemistry},
  publisher = {Elsevier},
  address   = {New York},
  issn      = {0955-2863},
  doi       = {10.1016/j.jnutbio.2015.11.010},
  pages     = {116 -- 123},
  year      = {2016},
  abstract  = {The essential trace element zinc is indispensable for proper immune function as zinc deficiency accompanies immune defects and dysregulations like allergies, autoimmunity and an increased presence of transplant rejection. This point to the importance of the physiological and dietary control of zinc levels for a functioning immune system. This study investigates the capacity of zinc to induce immune tolerance. The beneficial impact of physiological zinc supplementation of 6 mu g/day (0.3 mg/kg body weight) or 30 mu g/day (1.5 mg/kg body weight) on murine experimental autoimmune encephalomyelitis (EAE), an animal model for multiple sclerosis with a Th1/Th17 (Th, T helper) cell-dominated immunopathogenesis, was analyzed. Zinc administration diminished EAE scores in C57BL/6 mice in vivo (P<.05), reduced Th17 ROR gamma T+ cells (P<.05) and significantly increased inducible iTreg cells (P<.05). While Th17 cells decreased systemically, iTreg cells accumulated in the central nervous system. Cumulatively, zinc supplementation seems to be capable to induce tolerance in unwanted immune reactions by increasing iTreg cells. This makes zinc a promising future tool for treating autoimmune diseases without suppressing the immune system. (C) 2015 Elsevier Inc. All rights reserved.},
  language  = {en}
}
@article{EbertMeyerLeffersetal.2016,
  author    = {Ebert, Franziska and Meyer, S{\"o}ren and Leffers, Larissa and Raber, Georg and Francesconi, Kevin A. and Schwerdtle, Tanja},
  title     = {Toxicological characterisation of a thio-arsenosugar-glycerol in human cells},
  series = {Journal of trace elements in medicine and biology},
  volume    = {38},
  journal   = {Journal of trace elements in medicine and biology},
  publisher = {Springer Publishing Company},
  address   = {Jena},
  issn      = {0946-672X},
  doi       = {10.1016/j.jtemb.2016.04.013},
  pages     = {150 -- 156},
  year      = {2016},
  abstract  = {Arsenosugars are water-soluble arsenic species predominant in marine algae and other seafood including mussels and oysters. They typically occur at levels ranging from 2 to 50 mg arsenic/kg dry weight. Most of the arsenosugars contain arsenic as a dimethylarsinoyl group (Me2As(O)-), commonly referred to as the oxo forms, but thio analogues have also been identified in marine organisms and as metabolic products of oxo-arsenosugars. So far, no data regarding toxicity and toxicokinetics of thio-arsenosugars are available. This in vitro-based study indicates that thio-dimethylarsenosugar-glycerol exerts neither pronounced cytotoxicity nor genotoxicity even though this arsenical was bioavailable to human hepatic (HepG2) and urothelial (UROtsa) cells. Experiments with the Caco-2 intestinal barrier model mimicking human absorption indicate for the thio-arsenosugar-glycerol higher intestinal bioavailability as compared to the oxo-arsenosugars. Nevertheless, absorption estimates were much lower in comparison to other arsenicals including arsenite and arsenic-containing hydrocarbons. Arsenic speciation in cell lysates revealed that HepG2 cells are able to metabolise the thio-arsenosugar-glycerol to some extent to dimethylarsinic acid (DMA). These first in vitro data cannot fully exclude risks to human health related to the presence of thio-arsenosugars in food. (C) 2016 Elsevier GmbH. All rights reserved.},
  language  = {en}
}
@article{EbertThomannWittetal.2016,
  author    = {Ebert, Franziska and Thomann, Marlies and Witt, Barbara and M{\"u}ller, Sandra Marie and Meyer, S{\"o}ren and Weber, Till and Christmann, Markus and Schwerdtle, Tanja},
  title     = {Evaluating long-term cellular effects of the arsenic species thio-DMA(V): qPCR-based gene expression as screening tool},
  series = {Journal of trace elements in medicine and biology},
  volume    = {37},
  journal   = {Journal of trace elements in medicine and biology},
  publisher = {Yokohama Publishers},
  address   = {Jena},
  issn      = {0946-672X},
  doi       = {10.1016/j.jtemb.2016.06.004},
  pages     = {78 -- 84},
  year      = {2016},
  abstract  = {Thio-dimethylarsinic acid (thio-DMA(V)) is a human urinary metabolite of the class 1 human carcinogen inorganic arsenic as well as of arsenosugars. Thio-DMA(V) exerts strong cellular toxicity, whereas its toxic modes of action are not fully understood. For the first time, this study characterises the impact of a long-term (21 days) in vitro incubation of thio-DMA(V) on the expression of selected genes related to cell death, stress response, epigenetics and DNA repair. The observed upregulation of DNMT1 might be a cellular compensation to counterregulate the in a very recent study observed massive global DNA hypomethylation after chronic thio-DMAv incubation. Moreover, our data suggest that chronic exposure towards subcytotoxic, pico- to nanomolar concentrations of thio-DMA(V) causes a stress response in human urothelial cells. The upregulation of genes encoding for proteins of DNA repair (Apex1,Lig1, XRCC1,DDB2, XPG, ATR) as well as damage response (GADD45A, GADD45G, Trp53) indicate a potential genotoxic risk emanating from thio-DMA(V) after long-term incubation. (C) 2016 Elsevier GmbH. All rights reserved.},
  language  = {en}
}
@article{NiehoffSchulzSoltwischetal.2016,
  author    = {Niehoff, Ann-Christin and Schulz, Jacqueline and Soltwisch, Jens and Meyer, Soren and Kettling, Hans and Sperling, Michael and Jeibmann, Astrid and Dreisewerd, Klaus and Francesconi, Kevin A. and Schwerdtle, Tanja and Karst, Uwe},
  title     = {Imaging by Elemental and Molecular Mass Spectrometry Reveals the Uptake of an Arsenolipid in the Brain of Drosophila melanogaster},
  series = {Analytical chemistry},
  volume    = {88},
  journal   = {Analytical chemistry},
  publisher = {American Chemical Society},
  address   = {Washington},
  issn      = {0003-2700},
  doi       = {10.1021/acs.analchem.6b00333},
  pages     = {5258 -- 5263},
  year      = {2016},
  abstract  = {Arsenic-containing lipids (arsenolipids) are natural products of marine organisms such as fish, invertebrates, and algae, many of which are important seafoods. A major group of arsenolipids, namely, the arsenic-containing hydrocarbons (AsHC), have recently been shown to be cytotoxic to human liver and bladder cells, a result that has stimulated interest in the chemistry and toxicology of these compounds. In this study, elemental laser ablation-inductively coupled plasma mass spectrometry (LA-ICPMS) and molecular matrix-assisted laser desorption/ionization (MALDI-)MS were used to image and quantify the uptake of an AsHC in the model organism Drosophila melanogaster. Using these two complementary methods, both an enrichment of arsenic and the presence of the AsHC in the brain were revealed, indicating that the intact arsenolipid had crossed the blood-brain barrier. Simultaneous acquisition of quantitative elemental concentrations and molecular distributions could allow new insight into organ-specific enrichment and possible transportation processes of arsenic-containing bioactive compounds in living organisms.},
  language  = {en}
}
@misc{MeyerSchulzJeibmannetal.2014,
  author    = {Meyer, S{\"o}ren and Schulz, Jacqueline and Jeibmann, Astrid and Taleshi, Mojtaba S. and Ebert, Franziska and Francesconi, Kevin and Schwerdtle, Tanja},
  title     = {Arsenic-containing hydrocarbons are toxic in the in vivo model Drosophila melanogaster},
  volume    = {11},
  number    = {6},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-76819},
  pages     = {2010 -- 2014},
  year      = {2014},
  abstract  = {Arsenic-containing hydrocarbons (AsHC) constitute one group of arsenolipids that have been identified in seafood. In this first in vivo toxicity study for AsHCs, we show that AsHCs exert toxic effects in Drosophila melanogaster in a concentration range similar to that of arsenite. In contrast to arsenite, however, AsHCs cause developmental toxicity in the late developmental stages of Drosophila melanogaster. This work illustrates the need for a full characterisation of the toxicity of AsHCs in experimental animals to finally assess the risk to human health related to the presence of arsenolipids in seafood.},
  language  = {en}
}
@article{MeyerSchulzJeibmannetal.2014,
  author    = {Meyer, S{\"o}ren and Schulz, Jacqueline and Jeibmann, Astrid and Taleshi, Mojtaba S. and Ebert, Franziska and Francesconi, Kevin and Schwerdtle, Tanja},
  title     = {Arsenic-containing hydrocarbons are toxic in the in vivo model Drosophila melanogaster},
  series = {Metallomics},
  journal   = {Metallomics},
  editor    = {Schwerdtle, Tanja},
  publisher = {The Royal Society of Chemistry},
  address   = {Cambridge},
  issn      = {1756-5901},
  pages     = {2010 -- 2014},
  year      = {2014},
  abstract  = {Arsenic-containing hydrocarbons (AsHC) constitute one group of arsenolipids that have been identified in seafood. In this first in vivo toxicity study for AsHCs, we show that AsHCs exert toxic effects in Drosophila melanogaster in a concentration range similar to that of arsenite. In contrast to arsenite, however, AsHCs cause developmental toxicity in the late developmental stages of Drosophila melanogaster. This work illustrates the need for a full characterisation of the toxicity of AsHCs in experimental animals to finally assess the risk to human health related to the presence of arsenolipids in seafood.},
  language  = {en}
}
@article{MeyerRaberEbertetal.2015,
  author    = {Meyer, S{\"o}ren and Raber, Georg and Ebert, Franziska and Leffers, L. and Mueller, Sandra Maria and Taleshi, M. S. and Francesconi, Kevin A. and Schwerdtle, Tanja},
  title     = {In vitro toxicological characterisation of arsenic-containing fatty acids and three of their metabolites},
  series = {Toxicology research},
  volume    = {4},
  journal   = {Toxicology research},
  number    = {5},
  publisher = {Royal Society of Chemistry},
  address   = {Cambridge},
  issn      = {2045-452X},
  doi       = {10.1039/c5tx00122f},
  pages     = {1289 -- 1296},
  year      = {2015},
  abstract  = {Arsenic-containing fatty acids are a group of fat-soluble arsenic species (arsenolipids) which are present in marine fish and other seafood. Recently, it has been shown that arsenic-containing hydrocarbons, another group of arsenolipids, exert toxicity in similar concentrations comparable to arsenite although the toxic modes of action differ. Hence, a risk assessment of arsenolipids is urgently needed. In this study the cellular toxicity of a saturated (AsFA 362) and an unsaturated (AsFA 388) arsenic-containing fatty acid and three of their proposed metabolites (DMA(V), DMAPr and thio-DMAPr) were investigated in human liver cells (HepG2). Even though both arsenic-containing fatty acids were less toxic as compared to arsenic-containing hydrocarbons and arsenite, significant effects were observable at mu M concentrations. DMA(V) causes effects in a similar concentration range and it could be seen that it is metabolised to its highly toxic thio analogue thio-DMA(V) in HepG2 cells. Nevertheless, DMAPr and thio-DMAPr did not exert any cytotoxicity. In summary, our data indicate that risks to human health related to the presence of arsenic-containing fatty acids in marine food cannot be excluded. This stresses the need for a full in vitro and in vivo toxicological characterisation of these arsenolipids.},
  language  = {en}
}
@misc{MayerUciechowskiMeyeretal.2014,
  author    = {Mayer, Lena S. and Uciechowski, Peter and Meyer, S{\"o}ren and Schwerdtle, Tanja and Rink, Lothar and Haase, Hajo},
  title     = {Differential impact of zinc deficiency on phagocytosis, oxidative burst, and production of pro-inflammatory cytokines by human monocytes},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-99405},
  year      = {2014},
  abstract  = {Zinc deficiency has a fundamental influence on the immune defense, with multiple effects on different immune cells, resulting in a major impairment of human health. Monocytes and macrophages are among the immune cells that are most fundamentally affected by zinc, but the impact of zinc on these cells is still far from being completely understood. Therefore, this study investigates the influence of zinc deficiency on monocytes of healthy human donors. Peripheral blood mononuclear cells, which include monocytes, were cultured under zinc deficient conditions for 3 days. This was achieved by two different methods: by application of the membrane permeable chelator N,N,N0´,N0´-tetrakis-(2-pyridylmethyl)ethylenediamine (TPEN) or by removal of zinc from the culture medium using a CHELEX 100 resin. Subsequently, monocyte functions were analyzed in response to Escherichia coli, Staphylococcus aureus, and Streptococcus pneumoniae. Zinc depletion had differential effects. On the one hand, elimination of bacterial pathogens by phagocytosis and oxidative burst was elevated. On the other hand, the production of the inflammatory cytokines tumor necrosis factor (TNF)-a and interleukin (IL)-6 was reduced. This suggests that monocytes shift from intercellular communication to basic innate defensive functions in response to zinc deficiency. These results were obtained regardless of the method by which zinc deficiency was achieved. However, CHELEX-treated medium strongly augmented cytokine production, independently from its capability for zinc removal. This side-effect severely limits the use of CHELEX for investigating the effects of zinc deficiency on innate immunity.},
  language  = {en}
}
@article{MehnerAttermeyerBraunsetal.2016,
  author    = {Mehner, T. and Attermeyer, Katrin and Brauns, Mario and Brothers, Soren M. and Diekmann, J. and Gaedke, Ursula and Grossart, Hans-Peter and Koehler, J. and Lischke, Betty and Meyer, N. and Scharnweber, Inga Kristin and Syvaranta, J. and Vanni, M. J. and Hilt, S.},
  title     = {Weak Response of Animal Allochthony and Production to Enhanced Supply of Terrestrial Leaf Litter in Nutrient-Rich Lakes},
  series = {Ecosystems},
  volume    = {19},
  journal   = {Ecosystems},
  publisher = {Springer},
  address   = {New York},
  issn      = {1432-9840},
  doi       = {10.1007/s10021-015-9933-2},
  pages     = {311 -- 325},
  year      = {2016},
  abstract  = {Ecosystems are generally linked via fluxes of nutrients and energy across their boundaries. For example, freshwater ecosystems in temperate regions may receive significant inputs of terrestrially derived carbon via autumnal leaf litter. This terrestrial particulate organic carbon (POC) is hypothesized to subsidize animal production in lakes, but direct evidence is still lacking. We divided two small eutrophic lakes each into two sections and added isotopically distinct maize litter to the treatment sections to simulate increased terrestrial POC inputs via leaf litter in autumn. We quantified the reliance of aquatic consumers on terrestrial resources (allochthony) in the year subsequent to POC additions by applying mixing models of stable isotopes. We also estimated lake-wide carbon (C) balances to calculate the C flow to the production of the major aquatic consumer groups: benthic macroinvertebrates, crustacean zooplankton, and fish. The sum of secondary production of crustaceans and benthic macroinvertebrates supported by terrestrial POC was higher in the treatment sections of both lakes. In contrast, total secondary and tertiary production (supported by both autochthonous and allochthonous C) was higher in the reference than in the treatment sections of both lakes. Average aquatic consumer allochthony per lake section was 27-40\%, although terrestrial POC contributed less than about 10\% to total organic C supply to the lakes. The production of aquatic consumers incorporated less than 5\% of the total organic C supply in both lakes, indicating a low ecological efficiency. We suggest that the consumption of terrestrial POC by aquatic consumers facilitates a strong coupling with the terrestrial environment. However, the high autochthonous production and the large pool of autochthonous detritus in these nutrient-rich lakes make terrestrial POC quantitatively unimportant for the C flows within food webs.},
  language  = {en}
}
@article{BornhorstEbertMeyeretal.2020,
  author    = {Bornhorst, Julia and Ebert, Franziska and Meyer, S{\"o}ren and Ziemann, Vanessa and Xiong, Chan and Guttenberger, Nikolaus and Raab, Andrea and Baesler, Jessica and Aschner, Michael and Feldmann, J{\"o}rg and Francesconi, Kevin and Raber, Georg and Schwerdtle, Tanja},
  title     = {Toxicity of three types of arsenolipids},
  series = {Metallomics},
  volume    = {12},
  journal   = {Metallomics},
  number    = {5},
  publisher = {Oxford University Press},
  address   = {Cambridge},
  issn      = {1756-591X},
  doi       = {https://doi.org/10.1039/d0mt00039f},
  pages     = {794 -- 798},
  year      = {2020},
  abstract  = {Although fish and seafood are well known for their nutritional benefits, they contain contaminants that might affect human health. Organic lipid-soluble arsenic species, so called arsenolipids, belong to the emerging contaminants in these food items; their toxicity has yet to be systematically studied. Here, we apply the in vivo model Caenorhabditis elegans to assess the effects of two arsenic-containing hydrocarbons (AsHC), a saturated arsenic-containing fatty acid (AsFA), and an arsenic-containing triacylglyceride (AsTAG) in a whole organism. Although all arsenolipids were highly bioavailable in Caenorhabditis elegans, only the AsHCs were substantially metabolized to thioxylated or shortened metabolic products and induced significant toxicity, affecting both survival and development. Furthermore, the AsHCs were several fold more potent as compared to the toxic reference arsenite. This study clearly indicates the need for a full hazard identification of subclasses of arsenolipids to assess whether they pose a risk to human health.},
  language  = {en}
}
@article{BrothersHiltAttermeyeretal.2013,
  author    = {Brothers, Soren M. and Hilt, Sabine and Attermeyer, Katrin and Grossart, Hans-Peter and Kosten, Sarian and Lischke, Betty and Mehner, Thomas and Meyer, Nils and Scharnweber, Inga Kristin and K{\"o}hler, Jan},
  title     = {A regime shift from macrophyte to phytoplankton dominance enhances carbon burial in a shallow, eutrophic lake},
  series = {Ecosphere : the magazine of the International Ecology University},
  volume    = {4},
  journal   = {Ecosphere : the magazine of the International Ecology University},
  number    = {11},
  publisher = {Wiley},
  address   = {Washington},
  issn      = {2150-8925},
  doi       = {10.1890/ES13-00247.1},
  pages     = {17},
  year      = {2013},
  abstract  = {Ecological regime shifts and carbon cycling in aquatic systems have both been subject to increasing attention in recent years, yet the direct connection between these topics has remained poorly understood. A four-fold increase in sedimentation rates was observed within the past 50 years in a shallow eutrophic lake with no surface in-or outflows. This change coincided with an ecological regime shift involving the complete loss of submerged macrophytes, leading to a more turbid, phytoplankton-dominated state. To determine whether the increase in carbon (C) burial resulted from a comprehensive transformation of C cycling pathways in parallel to this regime shift, we compared the annual C balances (mass balance and ecosystem budget) of this turbid lake to a similar nearby lake with submerged macrophytes, a higher transparency, and similar nutrient concentrations. C balances indicated that roughly 80\% of the C input was permanently buried in the turbid lake sediments, compared to 40\% in the clearer macrophyte-dominated lake. This was due to a higher measured C burial efficiency in the turbid lake, which could be explained by lower benthic C mineralization rates. These lower mineralization rates were associated with a decrease in benthic oxygen availability coinciding with the loss of submerged macrophytes. In contrast to previous assumptions that a regime shift to phytoplankton dominance decreases lake heterotrophy by boosting whole-lake primary production, our results suggest that an equivalent net metabolic shift may also result from lower C mineralization rates in a shallow, turbid lake. The widespread occurrence of such shifts may thus fundamentally alter the role of shallow lakes in the global C cycle, away from channeling terrestrial C to the atmosphere and towards burying an increasing amount of C.},
  language  = {en}
}
@article{MuellerEbertRaberetal.2018,
  author    = {M{\"u}ller, Sandra Marie and Ebert, Franziska and Raber, Georg and Meyer, S{\"o}ren and Bornhorst, Julia and H{\"u}wel, Stephan and Galla, Hans-Joachim and Francesconi, Kevin A. and Schwerdtle, Tanja},
  title     = {Effects of arsenolipids on in vitro blood-brain barrier model},
  series = {Archives of toxicology : official journal of EUROTOX},
  volume    = {92},
  journal   = {Archives of toxicology : official journal of EUROTOX},
  number    = {2},
  publisher = {Springer},
  address   = {Heidelberg},
  issn      = {0340-5761},
  pages     = {823 -- 832},
  year      = {2018},
  abstract  = {Arsenic-containing hydrocarbons (AsHCs), a subgroup of arsenolipids (AsLs) occurring in fish and edible algae, possess a substantial neurotoxic potential in fully differentiated human brain cells. Previous in vivo studies indicating that AsHCs cross the blood-brain barrier of the fruit fly Drosophila melanogaster raised the question whether AsLs could also cross the vertebrate blood-brain barrier (BBB). In the present study, we investigated the impact of several representatives of AsLs (AsHC 332, AsHC 360, AsHC 444, and two arsenic-containing fatty acids, AsFA 362 and AsFA 388) as well as of their metabolites (thio/oxo-dimethylpropionic acid, dimethylarsinic acid) on porcine brain capillary endothelial cells (PBCECs, in vitro model for the blood-brain barrier). AsHCs exerted the strongest cytotoxic effects of all investigated arsenicals as they were up to fivefold more potent than the toxic reference species arsenite (iAsIII). In our in vitro BBB-model, we observed a slight transfer of AsHC 332 across the BBB after 6 h at concentrations that do not affect the barrier integrity. Furthermore, incubation with AsHCs for 72 h led to a disruption of the barrier at sub-cytotoxic concentrations. The subsequent immunocytochemical staining of three tight junction proteins revealed a significant impact on the cell membrane. Because AsHCs enhance the permeability of the in vitro blood-brain barrier, a similar behavior in an in vivo system cannot be excluded. Consequently, AsHCs might facilitate the transfer of accompanying foodborne toxicants into the brain.},
  language  = {en}
}
@article{KuhnTavaresJacquesTeixeiraetal.2021,
  author    = {Kuhn, Eug{\^e}nia Carla and Tavares Jacques, Maur{\´i}cio and Teixeira, Daniela and Meyer, S{\"o}ren and Gralha, Thiago and Roehrs, Rafael and Camargo, Sandro and Schwerdtle, Tanja and Bornhorst, Julia and {\´A}vila, Daiana Silva},
  title     = {Ecotoxicological assessment of Uruguay River and affluents pre- and biomonitoring},
  series = {Environmental science and pollution research : ESPR},
  volume    = {28},
  journal   = {Environmental science and pollution research : ESPR},
  number    = {17},
  publisher = {Springer},
  address   = {Berlin ; Heidelberg},
  issn      = {0944-1344},
  doi       = {10.1007/s11356-020-11986-4},
  pages     = {21730 -- 21741},
  year      = {2021},
  abstract  = {Uruguay River is the most important river in western Rio Grande do Sul, separating Brazil from Argentina and Uruguay. However, its pollution is of great concern due to agricultural activities in the region and the extensive use of pesticides. In a long term, this practice leads to environmental pollution, especially to the aquatic system. The objective of this study was to analyze the physicochemical characteristics, metals and pesticides levels in water samples obtained before and after the planting and pesticides' application season from three sites: Uruguay River and two minor affluents, Mezomo Dam and Salso Stream. For biomonitoring, the free-living nematode Caenorhabditis elegans was used, which were exposed for 24 h. We did not find any significant alteration in physicochemical parameters. In the pre- and post-pesticides' samples we observed a residual presence of three pesticides (tebuconazole, imazethapyr, and clomazone) and metals which levels were above the recommended (As, Hg, Fe, and Mn). Exposure to both pre- and post-pesticides' samples impaired C. elegans reproduction and post-pesticides samples reduced worms' survival rate and lifespan. PCA analysis indicated that the presence of metals and pesticides are important variables that impacted C. elegans biological endpoints. Our data demonstrates that Uruguay River and two affluents are contaminated independent whether before or after pesticides' application season. In addition, it reinforces the usefulness of biological indicators, since simple physicochemical analyses are not sufficient to attest water quality and ecological safety.},
  language  = {en}
}
@article{BrothersKoehlerAttermeyeretal.2014,
  author    = {Brothers, Soren M. and Koehler, J. and Attermeyer, Katrin and Grossart, Hans-Peter and Mehner, T. and Meyer, N. and Scharnweber, Inga Kristin and Hilt, Sabine},
  title     = {A feedback loop links brownification and anoxia in a temperate, shallow lake},
  series = {Limnology and oceanography},
  volume    = {59},
  journal   = {Limnology and oceanography},
  number    = {4},
  publisher = {Wiley-Blackwell},
  address   = {Hoboken},
  issn      = {0024-3590},
  doi       = {10.4319/lo.2014.59.4.1388},
  pages     = {1388 -- 1398},
  year      = {2014},
  abstract  = {This study examines a natural, rapid, fivefold increase in dissolved organic carbon (DOC) concentrations in a temperate shallow lake, describing the processes by which increased DOC resulted in anoxic conditions and altered existing carbon cycling pathways. High precipitation for two consecutive years led to rising water levels and the flooding of adjacent degraded peatlands. Leaching from the flooded soils provided an initial increase in DOC concentrations (from a 2010 mean of 12 +/- 1 mg L-1 to a maximum concentration of 53 mg L-1 by June 2012). Increasing water levels, DOC, and phytoplankton concentrations reduced light reaching the sediment surface, eliminating most benthic primary production and promoting anoxia in the hypolimnion. From January to June 2012 there was a sudden increase in total phosphorus (from 57 mg L-1 to 216 mg L-1), DOC (from 24.6 mg L-1 to 53 mg L-1), and iron (from 0.12 mg L-1 to 1.07 mg L-1) concentrations, without any further large fluxes in water levels. We suggest that anoxic conditions at the sediment surface and flooded soils produced a dramatic release of these chemicals that exacerbated brownification and eutrophication, creating anoxic conditions that persisted roughly 6 months below a water depth of 1 m and extended periodically to the water surface. This brownification-anoxia feedback loop resulted in a near-complete loss of macroinvertebrate and fish populations, and increased surface carbon dioxide (CO2) emissions by an order of magnitude relative to previous years.},
  language  = {en}
}